Substation switch-hook.



1. G. BLESSING. SUBSTAIION SWITCH HOOK. APPLICATION FILED MAR. 20, I916- Patented Feb. 19,1918.

1,56,;512 HE T J. G. BLESSING. SUBSTATION SWIICH HOOK. I APPLICATION FI'LED MAR. 20, 1916- 1,256,512. Patented Feb.19,191&

2 SHEETSSHEET 2.

JOHN G. BLESSING, F CHICAGO, ILLINOIS, ASSIGNOR PANY, 0F CHIGAGO, ILLINOIS, A CORPQRA T0 AUTOMATIC ELECTRIC COM- TION OI? ILLINOIS.

SUB$TATION SWITCE-HOOK.

Application filed March 20, 1916.

1 '0 (:ZZ 10/ 60771 it may concern:

Be it known that 1', Jenn G. BLnssine, a citizen of the. United States of America, and a resident of Chicago, Cook county, Illinois, have invented certain new and useful Tmprovenients in Substation ElwitclnHooks of which the following is a specification.

My invention relates to switch-hooks for telephone systems in general. but more particularly to switch-hooks for automatic telephone systems.

In automatic telephone systems it frequently happens that an impulse is inadvertently transmitted to the central oflice switching equipment when the substation receiver is being removed from the switch hook to initiate a co ll. This may be due to the switch-hook rms being bent too close together or it may be due to carelessness on the part of the person attempting to make the call. In event if the switch-hook is moved suliiciently to break the line circuit after the said circuit has been closed, in the act of removing the receiver, a false impulse will be transmitted over the line and the calling subscriber will fail to be connected with the station number for which the calling device is subsequently operated.

Generally stated therefore, the object of my invention is to provide positive and eflicient means for closing the line circuit in such a manner as to prevent the transmission of a false impulse to the central otiice switching mechanism.

It is also an object of my invention to pro vide an improved s vitch-hook controlled by a receiver wherein the line circuit will remain positively closed when once closed in the act of removing the receiver.

It is also an object to provide certain details and. features of improvementtending to increase the efliciency and general serviceability of a telephone system by providing a device of this character.

To the foregoing and other useful ends my invention consists of matters hereinafter set forth and claimed.

My invention will be more readily understood by reference to the accompanying drawings in which. Fi 'ure 1 represents a front view of a desk stand provided with my improved switch-hook. Fig. 2 illustrates a top view. Fig. 3 shows a front view partly in section with part of the desk stand cut away. Figs, 4 and 5 show one method of Specification of Letters Patent.

Serial Patented Feb. 19, 1918.

applying my improved switch hook to a system of well known type, it being understood that any well known type of switches may be substituted for those illustrated.

the above views the hooked portions 5 and 6 are rigidly by the screws 8 and 9.

secured to the desk-stand tube '7 The screw 10 holds the portions rigid with a space between them. The spring 11 provided with projecting pins 12 5 by mean moves freely in a 13, is secured to the portion the rivet 14.. The pin 13 hole drilled near the end of and s of portion 5 while the pin 12 moves freely in a cut out part of the said portion 5.

The pin 12 is arranged to engage the end 15 of the a rm 16.

The arms 16 and 17 are rigidly secured together and are pivoted in the tube at Fig. 3 a show the Pivoted to The arms 16 -17 when released move In to an extension 18 of arms 16 and 17 at a point 19, inside of the tube 7, is a plunger 20 the disk 21,

the tube 7.

tween the disk 21 which passes through a hole in which disk is rigidly secured to A spiral spring 22, placed be and the nut 28, tends normally to force the plunger 20 downward but is prevented from doing so as long as the pin 12 is over the end portion 15 of arm 16, as shown in Figs. 2 and 3. Between nuts 23 and 21, which are secured near the end of plunger 20, and arranged to be engaged by insulating bushings, engaging spring plunger 20 is moved spring 26 springs 25 a is a spring 25 normally and adapted when the downward to disengage and engage spring 27. When 11d 26 arein contact the ringer or bell circuit is closed and when spring 25 is out of engagement with s rin 26 but in en a emeat with spring 27 the bell circuit is open and the talking circuit is closed. The spring 11 is tensio 13 in the position shown in Fig. 2. he understood that ned to maintain the pins 12 and It is to the screw 10 holds the portions 5 and 6 at such. a distance from each other as to ceiver shell permit free up and down m0vecomprising the arms 16 portions 5 and 6 are at that the re but the said shell will engage the pro ecting pin 13 and gaging pro of arm 16,

force it outward thereby disenjecting pin 12 from the end 15 The spiral. spring 22 thereupon upward as shown in iheliees tt hq and draw the plunger 20 16-17 being carried Figs. 1 and 3. When the pin 13 is :trecd't'rom the receiver shell the spring 11 carries lroth pins 12 and 13 back to normal, so that when hook 16-17 is carried down by the estoration of the receiver the pin 12 will be eady to engage and hold the hook through its end portion 15. Fig. 1 indicates the position of the parts after the receiver is removed. Fig. 2 shows the parts when the receiver is upon the hook. Fig. 3 illustrates views ot' the apparatus partly in sect on and partly cut away. The receiver shell has been omitted to make the illustration clearer.

In order that the operation of my improved switch hcok may be more easily understood and the utility therefor more clearly seen, I have herein illustrated the same in connection with a telephone system comprising automatic switches of a well known character.

The substation A is providcdwith a receiver 28. transmit er 29, ringer 30, coneXerts its tension to downward, the hook denser 31, hook switch 17 pivoted at 1'8 and the component parts illustrated in Figs. 1, 2 and 3. Being an automa ic substation, it is also provided with a calling device 80 controlling a pair of impulse springs 79 for transmittirg impulses to the central o'llice switching apparatus. This calling device or impulse sender may be similar t that shown and descr bed in United States Letters Pat out No. 1,110 39 1 granted December 1, 191 1, to John G. B essing.

The substation A is provided at the cen tral ottice with an individual or line switch G which is of the general type of subscribers switch shown in British patent to T. G. Martin, No. M19 of 1910, being however. of the particular type disclos d in United States L tters Patent to F. Newforth, n, No. 13901, reissued April 13, 191.5.

The master switch. D is of the same general type disclosed in British patent to R TV. James, No. 26.301 of 1906Jbeing however, of the particular patent to T. G. lvlartin, No. 1 119 of 1910. The function of the master switch, as is well known, is to maintain the plungers of all idle line switch s in position to engage the terminals of an idle trunk line. p

The selector switch E is of the sametype of switch as that disclosed in British patent to Automatic Telephone Manufacturing Co, Ltd No. 25 13 01 1914;. i

The connector switch E (Fig. 5) is of the same type of connec or switch as that shown in British Patent No. 2543 above referred to. The private magnet '67 is connected in a somewhat different circuit in the switch herein illustrated, but this is of no particular importance.

all d. -.st' F at type shown in British in all respects similar to line switch G and station A. The line switch (lcomprises a magnet 32 having the pullin winding 33 and holding or cut-off winding 34. The pull-in winding 33 is strongenough to operate both the cut-oil arm 35' and the plunger arm 36 while the holding winding 31 is only strong enough to operate the cut-off arm 35 but will hold the plunger arm 36 in its operated position when the same has been operated by the pull-in winding 33. The line relay 37 is slow acting and closes the circuit or the pull-in winding when it is energized. The plunger arm 36 upon being operated thrusts its plunger (not shown) into a bank of contacts to extend a connection to a selector switch such as the switch E. The bank springs 38 39, a0 and 411 are thereby pressed into contact with springs 4-2, 13, 41 and a5 respectively. Thereby extending the connection to the line relay 416 of the selector E. The line relay 16, upon energizing, closes the circuit for the release relay 47 which, upon energizing, opens the circuit of release magnet 48, prepares a circuit for vertical magnet 19through slow acting relay 50 and supplies a holding ground from G for the holding winding 34. The controlling relay 51 maintains open the circuit of switching relay 52, until. the rotary magnet 53 has stepped the wiper 5%. 55 and 56 onto the bank contacts of an idle trunk line leading to a connector H. The oft-normal springs 57 and 58 are closed when the switch shaft takes one or more steps from its normal position. I The connector sw1tch H carries upon its shaft (not shown) the wipers .59. 60 and 61 adapted to engage a series of bank contacts arranged in horizontal rows or levels. The vertical and rotary movements of these wipers are controlled by the vertical and rotary magnets 62 and 63 which in turn are controlled by the line relay 61; The line relay 64: when energized, closes the circuit of slow acting release relay 65. The slow acting private control relay 66 controls the circuit of private magnet 67 and slow acting cut-off relay 68. The relay 69 is controlled by the interrupter 70 to apply ringing current from the generator R to signal the called line. The ringer cut-off relay 71 when energized opens the circuit of ringing relay 69. The lousy relay 72 energizes whenever the switch attempts to connect with a busy line. When energized the said relay 72, applies a busy tone from the busy machine I to the calling line. The back-bridge relay 73 is energized when the called subscriber answers. The release magnet 7-1 upon energizing restores the connector toits normal position. The switch shaft upon reaching normal, separates oii -normal spr'ngs 75 and 76.

The battery B having one pole grounded is used for supplying current for operating the automatic switc es and for talking purposes.

A general description of the automatic switches having been given and as they are of the type shown and described in the publications herein referred to, it is not deemed necessary to trace the details of a completed connection between two substations. The operation of my improved device will be clearly seen when it is assumed that a subscriber at substation A. (Fig. 1) removes his receiver from its hook support in order to set up an automatic connection.

When the receiver 28 is raised from its supporting arms 16 and 17, the arms 16 and 17 remain in their position due to the engagement of pin 12 with end portion of arm 16. When, however, the receiver is taken out of the arms 5 and 6, the receiver shell engages and forces pin 13 upward (as viewed in Fig. thereby carrying pin 12 upward far enough to disengage the end portion 15 of arm 16. The tension in spring 22 thereupon immediately draws the plunger oown (Fig. 3) and moves the arms 16 and 17 upward about the pivot 18. The spring is thereby separated from spring 26 and engages spring 27. Upon referring to the circuit diagram in Fig. 4:, it will be seen that when this happens the circuit of ringer 30 and condenser 31 is broken and the line circuit is closed. This line circuit extends from ground G through springs 77, line conductors 78, transmitter 29. receiver 28, i1npulse springs 79, hook switch springs 27 and 25, return line conductor 81, springs 82, and the line relay 87 to the battery B. The line relay, upon energizing, closes a circuit from ground G through springs 88, pull-in Winding 33 and contact 8% to the battery B. The plunger arm 36 thereupon thrusts its plunger into the bank of contacts 38 to and extends the connection to the line relay 46. The circuit for line relay 46 extends from ground G through its lower Winding, spring contacts 85, bank springs 45 and 41, line conductor 78 to and through station A, return conductor 81, tank springs 38 and 42, spring contacts 86 and the upper winding of said line relay 4:6 to the battery B. The relay l-G upon energizing, closes the circuit of release relay 47 which as before stated prepares the vertical magnet circuit and extends a holding ground to the winding 34 before slow acting relay 37 falls back to open the circuit of pull-in winding 38. The circuit above traced to the line relay 46 is formed immediately after the hook switch springs 25 and 27 close contact, and as the receiver is entirely free from the switch hook arms 16 and 17 when they are released, the possibility of breaking the line circuit in the act of removing the receiver to initiate a call is removed. It should be noted that if the springs 25 and 27 are momentarily separated after the line relay @6 is energized in series with said springs, the relay 46 will be mementarily dele'nergized and will send an impulse to the vertical magnet which will raise the shaft wipers to the first level Where they begin to select an idle trunk line which may extend to a connector switch in an altogether different hundred group from that in which the called line terminates. vVhen, therefore, the calling subscriber operates his calling de rice the first digit of impulses will operate to step up the connector instead of operating the selector. The second digit of impulses will rotate the connector while the last digit of impulses will be of no utility. The calling subscriber will therefore be connected with a wrong number. With my improved de vice wherein the receiver causes the release of the switch hook arms l6-17 by forcing the spring 11 to disengage its pin 12 from 15, it is seen that the receiver will be entirely out of its seat before the springs 25 and 27 are permitted to close the line circuit, thereby altogether removing the possibility of the switch E being falsely operated by the removal of the receiver.

The calling line is provided with a guarding ground potential upon its private bank contacts as soon as the switch E is seized. The called line is also provided with a ground potential as soon as the connector H establishes connection therewith. If the called line is busy, the private wiper of the connector will engage the bank contact supplied with the guarding potential and will cause the relay 72 to energize and the private magnet 67 to hold the side switch in the second position to prevent the connection from being extended to the busy line. The calling subscriber is given a busy signal from the busy machine I.

When the calling subscriber hangs up his receiver either after conversation is completed or after a busy line is found, the re ceiver upon being replaced to the arms 16 and 17 overcomes the tension of springs 22, thereby moving the plunger 20 (Fig. 3) upward to separate spring 25 from spring 27 and cause spring 25 to engage spring 26 thereby closing the ringer circuit. The hook comprising arms 16 and 17 is carried downward until the end 15 engages and forces the pin 12 outward. The end 15 is carried just beneath pin 12 when the said pin is then forced bv spring 11 to assume a posit on (Fig. 2) just above the end portion 15. The hook-arms 1617 are thus held mechanically locked in this position until the receiver is removed for another all.

It is thus seen that I have devised a very eficient form of hook-switch for telephone systems and one which is very positive and reliable in its operation.

' departing from While I have illustrated and described my invention in connection with an automatic telephone system of a particular character it is to be understood that my invention is plicable to other automatic telephone systems as well as to operator-controlled or manual telephone systems. 1 Also while my improved switch-hook is shown in its relation to a telephone system, I do not wish to be so limited as this device may be apof hooks, one or" said hooks being stationary,

another of said hooks being movable in a.

downward direction.

3. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary,-

another of said hooks being movable in a downward direction, and a spring for said stationary hook for controlling said movable hook.

4. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks arranged one within the other, one of said hooks for supporting-said receiver, another of said hooks having a spring for controlling said supporting book.

5. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality ofUshaped hooks, arranged one within the other, one of said hooks movable by and s i aporting said receiver.

6. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks arranged one within the other, one of said hooks movable by and supporting said receiver, another of said hooks having a flexible spring for controlling said supporting hook.

7. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary,

another of said hooks being movable, said stationary hook having a flexible spring with a pair of projecting pins, one of said pins arranged to be engaged by said receiver, the other of saidpins for holding said movable hook.

8. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable, said stationary hook having a flexible spring with a pair of projecting pins, one of said pins arranged to be engaged by said receiver, the other of said pins for holding said movable hook, whereby when. said receiver engages said first pin said movable hook is released.

9. In a telephone system, a station, a line connecting said station with the exchange,

a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable, said stationary hook having a flexible spring with a pair of projecting pins, one of said pins arranged to be engaged by said receiver, the other of said pins for holding said movable hook, whereby when said receiver engages said first pin said movable hook is released, and a spring for moving said movable hook.

10. In a telephone system, station, a line connecting said sta ion with the ex.- change, a receiver, a support'for said receiver at said station, said support comprising a plurality of'hooks, one of said hooks being stationary, another of said hooks being movable, and a spring for moving said movable hook in a vertical plane.

11. In a telephone system, a station, a line connecting said station with the exchange, a

receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooksbeing stationary, another of said hooks being movable, a spring for said stationary hook for control.- ling said movable hook, and a spring for moving said movable hook.

12. In a telephone system, a station, a linev connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable in a vertical plane, a plurality of contact springs controlled by said movable hook, circuits controlled bv said contact springs, and means for shifting said springs'to alter the circuit conditions.

13. In a telephone system, a station, aline connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of saidhooks being movable in a vertical plane, a spring for said stationary hook for controlling said movable hook, a plurality of contact springs controlled b said movable hook, circuits controlled by said contact springs, and means for shifting said springs to alter the circuit conditions.

14. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks arranged one Within the other, one of said hooks for supporting said receiver, another of said hooks having a spring for controlling said supporting hook, a plurality of contact springs controlled by said supporting hook, circuits controlled by said contact springs, and means for shifting said springs to alter the circuit conditions.

15. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks arranged one Within the other, one of said hooks movable by and supporting said receiver, a plurality of contact springs controlled by said supporting hook, circuits controlled by said contact springs, and means for shifting said springs to alter the circuit conditions.

16. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks arranged one Within the other, one of said hooks movable by and sup porting said receiver, another of said hooks having a flexible spring for controlling said supporting hook, a plurality of contact springs controlled by said supporting hook, circuits controlled by said contact springs, and means for shifting said springs to alter the circuit conditions.

17. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable, said stationary hook having a flexible spring with a pair of projecting pins, one of said pins arranged to be engaged by said receiver, the other of said pins for holding said movable hook, a plurality of contact springs controlled by said movable hook, circuits controlled by said contact springs, and means for shifting said springs to alter the circuit conditions.

18. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable, a plunger pivotally secured to sa d movable hook, and means for moving said movable hook through the medium of said plunger.

19. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, another of said hooks being movable, a spring for said stationary hook for controlling said movable hook, a plunger pivotally secured to said movable hook and means for moving said movable hook through the medium of said plunger.

20. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a receiver support for said station, said support comprising a plurality of ti-shaped hooks, one of said hooks for supporting said receiver, another of said hooks having spring for controlling said supporting hook, a plunger pivotally secured to said supporting hook, and means for moving said supporting hook through the medium of said plunger.

21. In a telephone system, a station, a line connecting said station With the exchange, a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks, one of said hooks movable by and supporting said receiver, another of 95 said hooks having a flexible spring for controlling said supporting hook, a plunger pivotally secured to said supporting hook, and means for moving said supporting hook through the medium of said plunger.

22. In a telephone system, a station, a line connecting said station with the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of sad hooks being stationary, another of said hooks being movable, said stationary hook having a flexible spring With a pair of projecting pins, one of said pins arranged to be engaged by said receiver, the other of said pins for holding said movable hook, a plunger pivotally se cured to said movable hook, and means for moving said movable hook through the medium of said plunger.

23. In a telephone system, a station, a line connecting said station With the exchange,

a receiver, a receiver support for said station, said support comprising a plurality of U-shaped hooks, one of said hooks movable by and supporting said receiver, another of said hooks having a flexible spring for controlling said supporting hook. a plunger pivotally secured to said movable hook, and means for moving said plunger when said movable hook is released.

24. In a telephone system, a station, a line connecting said station With the exchange, a receiver, a support for said receiver at said station, said support comprising a plurality of hooks, one of said hooks being stationary, 130

c'eiver, the other mg springs to control the transmitter cirsuit, a latch for holding said support while said receiver is removed therefrom and means for thereafter removing said latch from the path of said support to allow said support to close said transmitter circuit.

26. In a telephone system, a subscribers station having a transmitter and a receiver for conversational purposes, a line connect ing said station with the exchange, a support for said receiver, said support operating springs to control the circuit of said transmitter and receiver, a latch for engaging and holding said support while said receiver is removed therefrom and means for thereafter removing said latch from the path of said support to allow said support to close the circuit of said transmitter and .recjeiver. I

27. In a telephone system, a subscribers station, a line connecting said station with the exchange, a receiver, a support for said receiver, said support comprising a movable hook forholding said tionary hook having a flexible member for 40 holding said movable hook.

28 In telephone system, a subscribers station, a line connecting said station with the exchange, a receiver, a support for said receiver, said support comprising 7 a movable hook for holding said receiver and a stationary hook having a flexible member for holding said movable hook, said flexible member controlled by said receiver for re leasing said movable hook.

0 I 29. In a telephone system, a subscribers receiver and a sta Illinois, this 18th day station, a line connecting said station with the exchange, a receiver, a support for said receiver, said support comprising a movable hook for holding said receiver and a stationary hook having a flexible member for holding said movable hook, and means controlled by the replacing of said receiver for controlling said flexible member to hold said movable hook.

30. In a telephone system, a subscribers station, a line connecting said station with the exchange, a receiver, a support for said receiver, said support comprising a movable hook for holding said receiver and'a stationary hook having a flexible member for holding said movable hook, whereby "when said receiver moves said movable member into engagement with said flexible 'nieni'ber', the said movable member is mechanically locked- 31. In a telephone system, a subscribers station, a line connecting said station with the exchange, a receiver, a support for said receiver, a latch normally engaging with said support, means controlled by said re ceiver for removing said latch from engagement with said support to release said sup port. 7 I

32. In a telephone system, a subscribers station, a line connecting saidstation with the exchange, a receiver, a hook forsaid receiver, a latch normally engaging said hook to prevent its operation when the receiver is lifted tlie refrom,and means con trolled by said receiver for removing said latch from engagement with said hook to permitlthe operation of said hook.

325. In a telephone system, a subscriber-ls station, a line connecting said station with the exchange, a receiver, a hook for said receiver, circuits controlled by said hook, a latch'i'iormally engaging said hook to prevent its operation when the receiver is lifted therefrom, means controlled by said receiver for removing said latch from engagement with said hook and means for operating said hook to effect a circuit change.

Signed by me at Chicago, Cook county,

of March, 1916. OHNG. BLESSING.

copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

